Move files in wtf/ to platform/wtf/ (Part 5).

third_party/WebKit/Source/platform/wtf/NotNull.h

+/*
+ * Copyright (C) 2008 Apple Inc. All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef WTF_NotNull_h
+#define WTF_NotNull_h
+
+#include "platform/wtf/Assertions.h"
+
+// This version of placement new omits a 0 check.
+enum NotNullTag { NotNull };
+inline void* operator new(size_t, NotNullTag, void* location) {

[haraken, 2017/03/17 11:47:41]

I'm not sure if we want to create a dedicated file for only NotNullTag.

Are you planning to more things to this file? Or would it be an option to move
NotNullTag to Allocator.h?

[Yuta Kitamura, 2017/03/21 02:31:57]

I don't really want to put NotNull back to StdLibExtras.h, because
that header is quite messy. Putting NotNull in Allocator.h is certainly
an option, and it may be better than adding a new header.

Let me try to revise the patch...

+  DCHECK(location);
+  return location;
+}
+
+#endif  // WTF_NotNull_h